Should the dissimilarity between Jesus and early Christianity or between Jesus and Judaism be the central criteria for the historical Jesus? Gerd Theissen and Dagmar Winter argue that the criterion of dissimilarity does not do justice to the single most important result of more than two-hundred years of Jesus research: that the historical Jesus belongs to both Judaism and Christianity. The two authors propose a criterion of historical plausibility so that historical phenomenon under question can be considered authentic so long as it can be plausibly understood in its Jewish context and also facilitates a plausible explanation for its later effects in Christian history. This book is a cooperative project between Dagmar Winter and Gerd Theissen and represents the fruit of many years of their research on the historical Jesus.